1. Field of the Invention
The present invention relates to a catheter for treating a luminal system of a patient. Particularly, the present invention is directed to a catheter having a main body portion with a coil-defined guidewire passage. Moreover, the present invention provides an improved rapid exchange type catheter.
2. Description of Related Art
A variety of catheter devices are known in the art for treating the luminal system of a patient. Of such devices, many are directed to treating the cardiovascular system of a patient.
“Over the wire” catheters are generally known in the art. These devices are generally introduced into a patient after a guidewire has been introduced into the patient, and advanced to a treatment site within a patient where a treatment procedure (e.g., angioplasty and/or stent placement) is to be performed. The catheter is advanced over the guidewire to the treatment site, the treatment procedure is performed, and the catheter and guidewire are subsequently removed. Such systems can be disadvantageous. Because the guidewire lumen of an over the wire catheter must traverse the entire length of the catheter (which can exceed about 150 cm), either an extremely long guidewire (greater than 300 cm in length) or a guidewire extension must be used to permit the physician to maintain a grip on the guidewire and catheter during the treatment procedure.
To address this problem, rapid exchange catheters have been developed. Generally, a rapid exchange catheter has a relatively short guidewire lumen (e.g., less than 25 cm) near the distal end of the catheter, thus permitting the physician to use a standard length guidewire (e.g., 185-190 cm) to introduce a catheter and/or perform a catheter exchange.
Such conventional methods and systems generally have been considered satisfactory for their intended purpose. However, rapid exchange catheters still suffer from certain performance issues, such as a lack of pushability and kink resistance. Although solutions to this problem have been developed, such as by introducing metallic components (such as hypotubes) along the length of a catheter not supported by a guidewire, there still remains a continued need in the art for a catheter having enhanced pushability, kink resistance and versatility. The present invention provides a solution for these problems.